On 2024/11/13 14:14, Thomas Gleixner wrote:
On Mon, Nov 11 2024 at 12:01, Chen Wang wrote:
+struct sg2042_msi_data {
+ void __iomem *reg_clr; /* clear reg, see TRM, 10.1.33, GP_INTR0_CLR */
Please make these tail comments tabular aligned so they actually stand
out.
https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#comment-style
Got, will fix this.
+
+ u64 doorbell_addr; /* see TRM, 10.1.32, GP_INTR0_SET */
+
+ u32 irq_first; /* The vector number that MSIs starts */
+ u32 num_irqs; /* The number of vectors for MSIs */
+
+ unsigned long *msi_map;
+ struct mutex msi_map_lock; /* lock for msi_map */
+};
+
+static int sg2042_msi_allocate_hwirq(struct sg2042_msi_data *priv, int num_req)
+{
+ int first;
+
+ mutex_lock(&priv->msi_map_lock);
Please use
guard(mutex)(&priv->msi_map_lock);
which removes all the mutex_unlock() hackery and boils this down
Thanks, will double check.
+
+ first = bitmap_find_free_region(priv->msi_map, priv->num_irqs,
+ get_count_order(num_req));
+ if (first < 0) {
+ mutex_unlock(&priv->msi_map_lock);
+ return -ENOSPC;
+ }
+
+ mutex_unlock(&priv->msi_map_lock);
+
+ return priv->irq_first + first;
to
guard(mutex)(&priv->msi_map_lock);
first = bitmap_find_free_region(priv->msi_map, priv->num_irqs,
get_count_order(num_req));
return first >= 0 ? priv->irq_first + first : -ENOSPC;
See?
+}
+
+static void sg2042_msi_free_hwirq(struct sg2042_msi_data *priv,
+ int hwirq, int num_req)
+{
+ int first = hwirq - priv->irq_first;
+
+ mutex_lock(&priv->msi_map_lock);
Ditto.
+ bitmap_release_region(priv->msi_map, first, get_count_order(num_req));
+ mutex_unlock(&priv->msi_map_lock);
+}
+static void sg2042_msi_irq_compose_msi_msg(struct irq_data *data,
+ struct msi_msg *msg)
+{
+ struct sg2042_msi_data *priv = irq_data_get_irq_chip_data(data);
+
+ msg->address_hi = upper_32_bits(priv->doorbell_addr);
+ msg->address_lo = lower_32_bits(priv->doorbell_addr);
+ msg->data = 1 << (data->hwirq - priv->irq_first);
+
+ pr_debug("%s hwirq[%d]: address_hi[%#x], address_lo[%#x], data[%#x]\n",
+ __func__,
No point in having this line break. You have 100 characters. Please fix
this all over the place.
Got.
+ (int)data->hwirq, msg->address_hi, msg->address_lo, msg->data);
(int) ? Why can't you use the proper conversion specifier instead of %d?
Will double-check.
+static int sg2042_msi_middle_domain_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs, void *args)
+{
+ struct sg2042_msi_data *priv = domain->host_data;
+ int hwirq, err, i;
+
+ hwirq = sg2042_msi_allocate_hwirq(priv, nr_irqs);
+ if (hwirq < 0)
+ return hwirq;
+
+ for (i = 0; i < nr_irqs; i++) {
+ err = sg2042_msi_parent_domain_alloc(domain, virq + i, hwirq + i);
+ if (err)
+ goto err_hwirq;
+
+ pr_debug("%s: virq[%d], hwirq[%d]\n",
+ __func__, virq + i, (int)hwirq + i);
No line break required.
+ irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+ &sg2042_msi_middle_irq_chip, priv);
+ }
+static int sg2042_msi_init_domains(struct sg2042_msi_data *priv,
+ struct device_node *node)
+{
+ struct irq_domain *plic_domain, *middle_domain;
+ struct device_node *plic_node;
+ struct fwnode_handle *fwnode = of_node_to_fwnode(node);
https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#variable-declarations
Thanks, will double-check.
+ if (!of_find_property(node, "interrupt-parent", NULL)) {
+ pr_err("Can't find interrupt-parent!\n");
+ return -EINVAL;
+ }
+
+ plic_node = of_irq_find_parent(node);
+ if (!plic_node) {
+ pr_err("Failed to find the PLIC node!\n");
+ return -ENXIO;
+ }
+
+ plic_domain = irq_find_host(plic_node);
+ of_node_put(plic_node);
+ if (!plic_domain) {
+ pr_err("Failed to find the PLIC domain\n");
+ return -ENXIO;
+ }
+
+ middle_domain = irq_domain_create_hierarchy(plic_domain, 0, priv->num_irqs,
+ fwnode,
+ &pch_msi_middle_domain_ops,
+ priv);
So now you have created a domain. How is that supposed to be used by the
PCI layer?
Here I create the domain and attached it to the fwnode. In PCI driver,
it can set this msi controller as its ""interrupt-parent" and find the
domain attached as below:
static int pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
parent_node = of_irq_find_parent(dev->of_node);
parent_domain = irq_find_host(parent_node);
...
}
+ if (!middle_domain) {
+ pr_err("Failed to create the MSI middle domain\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+static int sg2042_msi_probe(struct platform_device *pdev)
+{
....
+ data->msi_map = bitmap_zalloc(data->num_irqs, GFP_KERNEL);
+ if (!data->msi_map)
+ return -ENOMEM;
+
+ return sg2042_msi_init_domains(data, pdev->dev.of_node);
In case of error this leaks data->msi_map, no?
Thanks, I will correct this.
+static struct platform_driver sg2042_msi_driver = {
+ .driver = {
+ .name = "sg2042-msi",
+ .of_match_table = of_match_ptr(sg2042_msi_of_match),
+ },
+ .probe = sg2042_msi_probe,
+};
Please see the documentation I pointed you to above and search for
struct initializers.
Thanks,
tglx
